1. Field
The present disclosure relates to a refrigerator.
2. Description of the Related Art
A refrigerator is an apparatus capable of storing articles to be stored such as food and drugs at a temperature equal to or lower than a predetermined temperature, and is recently being variously used in households or industrial sites. The refrigerator includes a storage compartment to store articles to be stored and a cooling unit to supply cold air to the storage compartment in order to keep the storage compartment at a temperature equal to or lower than a predetermined temperature, thereby storing the articles to be stored at the temperature equal to or lower than a predetermined temperature.
The storage compartment of the refrigerator may include a refrigerator compartment, a freezer compartment, or an alternating-temperature compartment. The refrigerator compartment is cooled to a temperature equal to or lower than a predetermined temperature in order to refrigerate articles to be stored, and the freezer compartment is cooled to a temperature lower than that of the refrigerator compartment to freeze and store articles to be stored. The alternating-temperature compartment may vary a temperature therein depending on types or characteristics of articles to be stored to store and preserve various types of articles to be stored in accordance with the characteristics thereof.
The cooling unit may repeat a process of evaporating and compressing refrigerant through a cooling cycle to keep the temperature of the storage compartment at a level desired by a user. The cooling unit may include an evaporator, a compressor, a condenser, and a four-way expansion valve in order to cyclically repeat evaporation and compression of the refrigerant.